Hot-air pipe



(No Model.)

J. P. SOHAFFER.

. HOT AIR PIPE. No. 499,854.

Patented June 20, 1893.

INVENTOR a-MO WITNESSES 7% Q5 mom-umou wAsnmmoN, n. c.

.Air Pipes; and I do hereby declare the follow- UNITED STATES I PATENTGrates.

JOHN P. SCHAFFER, OF PITTSBURG, PENNSYLVANIA.

HOT-AIR PIPE.

SPECIFICATION forming part of Letters Fatent No. 499,854, dated June 20,1893.

Application filed August 20. 1892.

To all whom it may concern.

Be it known that I, JOHN P. SOHAFFER, a resident of Pittsburg, in thecounty of Allegheny and State of Pennsylvania, have invented a new anduseful Improvement in Hoting to be a full, clear, and exact descriptionthereof.

My invention relates to hot-air pipes. The style of hot-air pipes mostcommonly employed for conveying heat from hot-air furnaces tothedifferent apartments of buildings consists in a pipe having an innerhotair flue and an outer air-flue, the outer airflue surrounding theinner hot-air flue and acting to prevent the hot-air flue from cominginto direct contact with any inflammable material.

The object of my invention is to provide a simple yet sure and efficientmeans of connecting the several lengths of such hot-air pipes.

My invention consists, generally stated, in a hot-air pipe having aninner hot-air flue and an outer air-flue, one end of said pipe having aseparate thickness of metal extending from the outer walls of said outerair-flue up over the edge of same, passing down close to the inner facethereof, thence up beyond the edges of said pipe sufficient distance toform a tongue or extension around the top of said pipe, thence downagain between the walls of said outer air-flue and up over the edge ofthe inner wall of said pipe and down over the same a short distance,said tongue or extension on said separate thickness of metal beingperforated; the opposite end of said pipe having a seat formed betweenthe inner and outer walls, whereby the perforated tongue or extension onone end of said hotair pipe is adapted to enter the seat of thepreceding orsncceeding section as the case may be and be supportedthereby.

To enable others skilled in the art to make and use my invention, I willdescribe the same more fully, referring to the accompanying drawings inwhich- Figure 1 is a perspective view of a hot-air pipe broken away.Fig. 2 is a vertical section of a hot-air pipe with my invention appliedthereto. Fig. 3 is an enlarged end view Serial No. 443,617- (No model.)

showing the separate thickness of metal in the seat of the next section.

Like letters indicate like parts in each.

- The hot-air pipe at is one of ordinary construction having the innerhot-air flue b and the surrounding or outer air-flue c. To retain theinner hot-air flue b within the outer air flue c in proper alignment andto provide for connecting together several lengths of such pipe, theseparate thickness of metal (1 is employed. This separate thickness ofmetal (1 extends from the outer face of the walls 0 of the outerair-flue 0 up over the edge of said wall and down close to the innerface thereof. From this point the said separate thickness of metal 01extends up above the edges of the pipe for a suitable distance when saidmetal is bent over to form the tongue or extension e and then passesdown adjacent to the outer face of the wall b of the inner hot-air flueb and'u p over the edge of said wall I) and down the inner face thereof.This separate thickness of metal may be soldered to the inner hot-airflue and outer air-flue at suitable points to retain said separatethickness of metal securely in place. The tongue or extension e isperforated to form the openings e whereby air can pass from the air-flueof one section to that of the next succeeding one when several sectionsare joined together. The pipe at is further provided at the opposite endwith a seat whereby when two or more sections of pipe are to beconnected the tongue or extension e of one section is adapted to engagewith theseat of the preceding or succeeding sec-.

tion as the case may be. This seat may be of any suitable construction,that shown being well adapted for the purpose, and which consists of aseparate thickness of metal f extending from the outer face of the wall0' of the outer air-flue up over the edge of the same and then inwardlybetween the Walls 1) c, and then up over the edge of the wall 1) wherebya channel or trough-shaped seat is formed to receive the tongue orextension 6 of the separate thickness of metal d. The

tongue or extension e fits snugly within the seat formed for it by theseparate thickness of metal f and for this reason said seat is made toconform in shape to that of the tongue or extension which may be curved,V shaped or otherwise in cross section. The separate thickness of metalf is provided with openings f which coincide 'with the openings e of theseparate thickness of metal (1, so that when two sections of pipe areconnected the openings f will coincide exactly with the openings 6' sothat the air can pass directly from the air flue of one section to thatof the next succeeding one. This separate thickness of metal f whichforms the seat for the other separate thickness of metal 61 may be alsosoldered at different points to hold it securely in place. It isapparent, however, that lugs or other forms of supports might beemployed Within the outer air-flue to form supports for the tongue orextension e of the separate thickness of metal cl. By the employment ofthe separatethicknessof metal at the sections of pipe may be'formed inlong lengths it only being necessary to secure said separate thicknessof metal in place in the manner described. The common practice atpresent is to bevel the ends of the inner hot-air flue and the outerair-flue, or otherwise converge their ends and unite them by overlappingthe edges thereof, but this practice is not adapted for the constructionof sections of ,any great length owing to the difficulty of drawing orbeveling the ends and uniting them. By the employmment of a separatethickness of metal all necessity of beveling the ends of the pipe orotherwise uniting them is avoided.

What I claim as my invention, and desire to secure by Letters Patent, is

A hot air pipe consisting of an inner hot air flue formed by one bodyportion and an the body portions to enter into a seat in the oppositeend of the adjoining pipe, said projecting tongue being perforated, theseat in the opposite end of the pipe being formed of a separate sheetmetal portion extending along the outer faces of each body portion andover the edge of the same, and. thence into the outer air flue so as toform a seat for the reception of the tongue at the other end of thepipe, such seat having perforations -therein, substantially as setforth.

:In testimony whereof I, the said JOHN P. SOHAFFER, have hereunto set myhand.

' JOHN P. SCI-IAFFER. E Witnesses:

R0131. P. NEVEN, J 1 I ROBT. D. TOTTEN.

